Wow. I thought interest in Moro pieces have waned in the past year but it looks like I'm wrong. Or maybe because it's harder and harder to track down a twistcore. The older pieces will always be in demand regardless of overall trends, I think. Like the OP said, Twistcore + Ivory pommel = very desirable, even moreso when taken into consideration the age.
Also, considering the age I believe it to be in relatively good condition. Not great, mind you but good enough to easily restore without being too invasive (i.e. a replacement crest at the back of the pommel, maybe a sheath, or even nice enough to leave it as-is). Collecting quality pieces has changed in the past couple of years in terms of moro blades, and compared to other twistcores that have sold in recent months (including one I remember seeing that was mostly eaten by rust and another with the tip completely shorn off) this one is actually not that bad. Not as good as acquisitions, say, in 2011 but pickings are slimmer and slimmer as popularity and knowledge about these rise.
If it's true about the pub wall theory, it's a shame about the hole but interesting that this was done nonetheless. Especially for such a great piece. If not, the mystery continues.
EDIT: Are there more examples of ethnographic arms with a confirmed "pub drill hole" that we can compare with?